1. Field of the Invention
The present invention relates to an apparatus for estimating a shape of an insertion portion.
2. Description of the Related Art
In general, a method of detecting an attitude or movement of an object by using an inertia sensor, or the like is known. According to the method, a plurality of sensors is arranged in a transformed object to estimate a shape of the object in a resting state.
For example, in Jpn. Pat. Appln. KOKAI Publication NO. 2007-151862, a technology regarding an endoscope in which acceleration sensors are disposed is disclosed. In the endoscope, an attitude of a part in which the acceleration sensor is disposed is detected based on an output of the acceleration sensor. Further, a displacement of the part in which the acceleration sensor is disposed is detected by integrating the output of the acceleration sensor.
Further, in Jpn. Pat. Appln. KOKAI Publication NO. 2011-059020, a technology regarding a 3D attitude estimation device is disclosed. The 3D attitude estimation device includes an acceleration sensor and an attitude angle estimation unit estimating a 3D attitude angle. Jpn. Pat. Appln. KOKAI Publication NO. 2011-059020 discloses a technology that measures acceleration depending on movement with high precision by removing a gravity acceleration component from acceleration detected by the acceleration sensor based on an attitude angle estimated by the attitude angle estimation unit.